diff --git a/senlin/drivers/base.py b/senlin/drivers/base.py
index a8d968d82..84d6b5897 100644
--- a/senlin/drivers/base.py
+++ b/senlin/drivers/base.py
@@ -41,7 +41,6 @@ class SenlinDriver(object):
         self.network = backend.network
         self.octavia = backend.octavia
         self.orchestration = backend.orchestration
-        self.telemetry = backend.telemetry
         self.identity = backend.identity
         self.message = backend.message
         self.workflow = backend.workflow
diff --git a/senlin/drivers/container/docker_v1.py b/senlin/drivers/container/docker_v1.py
index 8c831fb98..7240c539b 100644
--- a/senlin/drivers/container/docker_v1.py
+++ b/senlin/drivers/container/docker_v1.py
@@ -12,7 +12,7 @@
 
 import docker
 
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class DockerClient(object):
diff --git a/senlin/drivers/openstack/ceilometer_v2.py b/senlin/drivers/openstack/ceilometer_v2.py
deleted file mode 100644
index 65cdf946a..000000000
--- a/senlin/drivers/openstack/ceilometer_v2.py
+++ /dev/null
@@ -1,50 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-from senlin.drivers import base
-from senlin.drivers.openstack import sdk
-
-
-class CeilometerClient(base.DriverBase):
-    '''Ceilometer V2 driver.'''
-
-    def __init__(self, params):
-        super(CeilometerClient, self).__init__(params)
-        self.conn = sdk.create_connection(params)
-
-    @sdk.translate_exception
-    def alarm_create(self, **attrs):
-        return self.conn.telemetry.create_alarm(**attrs)
-
-    @sdk.translate_exception
-    def alarm_delete(self, value, ignore_missing=True):
-        return self.conn.telemetry.delete_alarm(value, ignore_missing)
-
-    @sdk.translate_exception
-    def alarm_find(self, name_or_id, ignore_missing=True):
-        return self.conn.telemetry.find_alarm(name_or_id, ignore_missing)
-
-    @sdk.translate_exception
-    def alarm_get(self, value):
-        return self.conn.telemetry.get_alarm(value)
-
-    @sdk.translate_exception
-    def alarm_list(self, **query):
-        return self.conn.telemetry.alarms(**query)
-
-    @sdk.translate_exception
-    def alarm_update(self, value, **attrs):
-        return self.conn.telemetry.update_alarm(value, **attrs)
-
-    @sdk.translate_exception
-    def sample_create(self, **attrs):
-        return self.conn.telemetry.create_sample(**attrs)
diff --git a/senlin/drivers/openstack_test/mistral_v2.py b/senlin/drivers/openstack_test/mistral_v2.py
deleted file mode 100644
index 2e18b0ede..000000000
--- a/senlin/drivers/openstack_test/mistral_v2.py
+++ /dev/null
@@ -1,80 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-
-from oslo_utils import uuidutils
-
-from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
-
-
-class MistralClient(base.DriverBase):
-    '''Fake mistral V2 driver for test.'''
-
-    def __init__(self, ctx):
-
-        self.fake_workflow = {
-            'created_at': '1970-01-01T00:00:00.000000',
-            'definition': 'workflow_def',
-            'id': 'ffaed25e-46f5-4089-8e20-b3b4722fd597',
-            'input': {
-                'cluster_id': '8c74607c-5a74-4490-9414-a3475b1926c2',
-                'node_id': 'fba2cc5d-706f-4631-9577-3956048d13a2',
-                'flavor_id': '1'
-            },
-            'name': "cluster-coldmigration",
-            'project_id': 'a7eb669e9819420ea4bd1453e672c0a7',
-            'scope': 'private',
-            'tags': [
-                'large',
-                'expensive'
-            ],
-            'updated_at': '1970-01-01T00:00:00.000000',
-        }
-
-        self.fake_workflow_create = {
-            'scope': 'private',
-            'id': 'ffaed25e-46f5-4089-8e20-b3b4722fd597',
-            'definition': 'workflow_def',
-        }
-
-        self.fake_execution_create = {
-            'id': 'ffaed25e-46f5-4089-8e20-b3b4722fd597',
-            'workflow_name': 'cluster-coldmigration',
-            'input': {
-                'cluster_id': '8c74607c-5a74-4490-9414-a3475b1926c2',
-                'node_id': 'fba2cc5d-706f-4631-9577-3956048d13a2',
-                'flavor_id': '1'
-            }
-        }
-
-    def wait_for_execution(self, execution, status='SUCCESS',
-                           failures=['ERROR'], interval=2,
-                           timeout=None):
-        return
-
-    def workflow_find(self, name_or_id, ignore_missing=True):
-        return sdk.FakeResourceObject(self.fake_workflow)
-
-    def workflow_delete(self, workflow, ignore_missing=True):
-        return
-
-    def execution_delete(self, execution, ignore_missing=True):
-        return
-
-    def workflow_create(self, definition, scope):
-        self.fake_workflow_create['id'] = uuidutils.generate_uuid()
-        return sdk.FakeResourceObject(self.fake_workflow_create)
-
-    def execution_create(self, name, inputs):
-        self.fake_execution_create['id'] = uuidutils.generate_uuid()
-        return sdk.FakeResourceObject(self.fake_execution_create)
diff --git a/senlin/drivers/openstack_test/sdk.py b/senlin/drivers/openstack_test/sdk.py
deleted file mode 100644
index 84c7b5fab..000000000
--- a/senlin/drivers/openstack_test/sdk.py
+++ /dev/null
@@ -1,28 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-
-class FakeResourceObject(object):
-    '''Generate a fake SDK resource object based on given dictionary'''
-    def __init__(self, params):
-        for key in params:
-            setattr(self, key, params[key])
-
-    def to_dict(self):
-        '''Override this function in subclass to handle special attributes'''
-        data = {}
-        for attr in dir(self):
-            if not attr.startswith('__'):
-                # Exclude built-in attributes of python object
-                data[attr] = getattr(self, attr)
-
-        return data
diff --git a/senlin/drivers/openstack/__init__.py b/senlin/drivers/os/__init__.py
similarity index 62%
rename from senlin/drivers/openstack/__init__.py
rename to senlin/drivers/os/__init__.py
index 09e644176..d593d3823 100644
--- a/senlin/drivers/openstack/__init__.py
+++ b/senlin/drivers/os/__init__.py
@@ -10,18 +10,18 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from senlin.drivers.openstack import ceilometer_v2
-from senlin.drivers.openstack import cinder_v2
-from senlin.drivers.openstack import heat_v1
-from senlin.drivers.openstack import keystone_v3
-from senlin.drivers.openstack import lbaas
-from senlin.drivers.openstack import mistral_v2
-from senlin.drivers.openstack import neutron_v2
-from senlin.drivers.openstack import nova_v2
-from senlin.drivers.openstack import octavia_v2
-from senlin.drivers.openstack import zaqar_v2
+from senlin.drivers.os import cinder_v2
+from senlin.drivers.os import heat_v1
+from senlin.drivers.os import keystone_v3
+from senlin.drivers.os import lbaas
+from senlin.drivers.os import mistral_v2
+from senlin.drivers.os import neutron_v2
+from senlin.drivers.os import nova_v2
+from senlin.drivers.os import octavia_v2
+from senlin.drivers.os import zaqar_v2
 
 
+block_storage = cinder_v2.CinderClient
 compute = nova_v2.NovaClient
 identity = keystone_v3.KeystoneClient
 loadbalancing = lbaas.LoadBalancerDriver
@@ -29,6 +29,4 @@ message = zaqar_v2.ZaqarClient
 network = neutron_v2.NeutronClient
 octavia = octavia_v2.OctaviaClient
 orchestration = heat_v1.HeatClient
-telemetry = ceilometer_v2.CeilometerClient
 workflow = mistral_v2.MistralClient
-block_storage = cinder_v2.CinderClient
diff --git a/senlin/drivers/openstack/cinder_v2.py b/senlin/drivers/os/cinder_v2.py
similarity index 97%
rename from senlin/drivers/openstack/cinder_v2.py
rename to senlin/drivers/os/cinder_v2.py
index da475a92e..daf9d467f 100644
--- a/senlin/drivers/openstack/cinder_v2.py
+++ b/senlin/drivers/os/cinder_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class CinderClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/glance_v2.py b/senlin/drivers/os/glance_v2.py
similarity index 96%
rename from senlin/drivers/openstack/glance_v2.py
rename to senlin/drivers/os/glance_v2.py
index 2ef13fd9b..5563f5022 100644
--- a/senlin/drivers/openstack/glance_v2.py
+++ b/senlin/drivers/os/glance_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class GlanceClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/heat_v1.py b/senlin/drivers/os/heat_v1.py
similarity index 98%
rename from senlin/drivers/openstack/heat_v1.py
rename to senlin/drivers/os/heat_v1.py
index ad7dead17..eececda89 100644
--- a/senlin/drivers/openstack/heat_v1.py
+++ b/senlin/drivers/os/heat_v1.py
@@ -13,7 +13,7 @@
 from oslo_config import cfg
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class HeatClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/keystone_v3.py b/senlin/drivers/os/keystone_v3.py
similarity index 99%
rename from senlin/drivers/openstack/keystone_v3.py
rename to senlin/drivers/os/keystone_v3.py
index f0a6163f2..af37b514a 100644
--- a/senlin/drivers/openstack/keystone_v3.py
+++ b/senlin/drivers/os/keystone_v3.py
@@ -14,7 +14,7 @@ from oslo_config import cfg
 from oslo_log import log
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 LOG = log.getLogger(__name__)
 CONF = cfg.CONF
diff --git a/senlin/drivers/openstack/lbaas.py b/senlin/drivers/os/lbaas.py
similarity index 99%
rename from senlin/drivers/openstack/lbaas.py
rename to senlin/drivers/os/lbaas.py
index d2cbbcdb0..b3e70aa2b 100644
--- a/senlin/drivers/openstack/lbaas.py
+++ b/senlin/drivers/os/lbaas.py
@@ -19,8 +19,8 @@ from oslo_log import log as logging
 from senlin.common import exception
 from senlin.common.i18n import _
 from senlin.drivers import base
-from senlin.drivers.openstack import neutron_v2 as neutronclient
-from senlin.drivers.openstack import octavia_v2 as octaviaclient
+from senlin.drivers.os import neutron_v2 as neutronclient
+from senlin.drivers.os import octavia_v2 as octaviaclient
 from senlin.engine import node as nodem
 
 LOG = logging.getLogger(__name__)
diff --git a/senlin/drivers/openstack/mistral_v2.py b/senlin/drivers/os/mistral_v2.py
similarity index 98%
rename from senlin/drivers/openstack/mistral_v2.py
rename to senlin/drivers/os/mistral_v2.py
index 81a864497..47dd7e4c5 100644
--- a/senlin/drivers/openstack/mistral_v2.py
+++ b/senlin/drivers/os/mistral_v2.py
@@ -11,8 +11,9 @@
 # under the License.
 
 from oslo_config import cfg
+
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class MistralClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/neutron_v2.py b/senlin/drivers/os/neutron_v2.py
similarity index 99%
rename from senlin/drivers/openstack/neutron_v2.py
rename to senlin/drivers/os/neutron_v2.py
index 3cbdd255f..33343d48a 100644
--- a/senlin/drivers/openstack/neutron_v2.py
+++ b/senlin/drivers/os/neutron_v2.py
@@ -13,7 +13,7 @@
 from oslo_utils import uuidutils
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class NeutronClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/nova_v2.py b/senlin/drivers/os/nova_v2.py
similarity index 99%
rename from senlin/drivers/openstack/nova_v2.py
rename to senlin/drivers/os/nova_v2.py
index 2bd49f640..7bf47b051 100644
--- a/senlin/drivers/openstack/nova_v2.py
+++ b/senlin/drivers/os/nova_v2.py
@@ -14,7 +14,7 @@ from oslo_config import cfg
 from oslo_log import log
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 LOG = log.getLogger(__name__)
 
diff --git a/senlin/drivers/openstack/octavia_v2.py b/senlin/drivers/os/octavia_v2.py
similarity index 99%
rename from senlin/drivers/openstack/octavia_v2.py
rename to senlin/drivers/os/octavia_v2.py
index fc211b1f5..5ba63dff0 100644
--- a/senlin/drivers/openstack/octavia_v2.py
+++ b/senlin/drivers/os/octavia_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class OctaviaClient(base.DriverBase):
diff --git a/senlin/drivers/openstack/zaqar_v2.py b/senlin/drivers/os/zaqar_v2.py
old mode 100755
new mode 100644
similarity index 98%
rename from senlin/drivers/openstack/zaqar_v2.py
rename to senlin/drivers/os/zaqar_v2.py
index e3b933745..af34b3fb2
--- a/senlin/drivers/openstack/zaqar_v2.py
+++ b/senlin/drivers/os/zaqar_v2.py
@@ -13,7 +13,7 @@
 from openstack import exceptions as sdk_exc
 
 from senlin.drivers import base
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 
 
 class ZaqarClient(base.DriverBase):
diff --git a/senlin/drivers/openstack_test/README.rst b/senlin/drivers/os_test/README.rst
similarity index 100%
rename from senlin/drivers/openstack_test/README.rst
rename to senlin/drivers/os_test/README.rst
diff --git a/senlin/drivers/openstack_test/__init__.py b/senlin/drivers/os_test/__init__.py
similarity index 61%
rename from senlin/drivers/openstack_test/__init__.py
rename to senlin/drivers/os_test/__init__.py
index 79e29fed6..cb2992136 100644
--- a/senlin/drivers/openstack_test/__init__.py
+++ b/senlin/drivers/os_test/__init__.py
@@ -10,17 +10,16 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from senlin.drivers.openstack import ceilometer_v2
-from senlin.drivers.openstack import keystone_v3
 
-from senlin.drivers.openstack_test import cinder_v2
-from senlin.drivers.openstack_test import heat_v1
-from senlin.drivers.openstack_test import lbaas
-from senlin.drivers.openstack_test import mistral_v2
-from senlin.drivers.openstack_test import neutron_v2
-from senlin.drivers.openstack_test import nova_v2
-from senlin.drivers.openstack_test import octavia_v2
-from senlin.drivers.openstack_test import zaqar_v2
+from senlin.drivers.os_test import cinder_v2
+from senlin.drivers.os_test import heat_v1
+from senlin.drivers.os_test import keystone_v3
+from senlin.drivers.os_test import lbaas
+from senlin.drivers.os_test import mistral_v2
+from senlin.drivers.os_test import neutron_v2
+from senlin.drivers.os_test import nova_v2
+from senlin.drivers.os_test import octavia_v2
+from senlin.drivers.os_test import zaqar_v2
 
 
 block_storage = cinder_v2.CinderClient
@@ -31,5 +30,4 @@ message = zaqar_v2.ZaqarClient
 network = neutron_v2.NeutronClient
 octavia = octavia_v2.OctaviaClient
 orchestration = heat_v1.HeatClient
-telemetry = ceilometer_v2.CeilometerClient
 workflow = mistral_v2.MistralClient
diff --git a/senlin/drivers/openstack_test/cinder_v2.py b/senlin/drivers/os_test/cinder_v2.py
similarity index 98%
rename from senlin/drivers/openstack_test/cinder_v2.py
rename to senlin/drivers/os_test/cinder_v2.py
index a3b3faea6..d2193fdf1 100644
--- a/senlin/drivers/openstack_test/cinder_v2.py
+++ b/senlin/drivers/os_test/cinder_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 
 class CinderClient(base.DriverBase):
diff --git a/senlin/drivers/openstack_test/heat_v1.py b/senlin/drivers/os_test/heat_v1.py
similarity index 98%
rename from senlin/drivers/openstack_test/heat_v1.py
rename to senlin/drivers/os_test/heat_v1.py
index f1f7f9f46..ef85ea936 100644
--- a/senlin/drivers/openstack_test/heat_v1.py
+++ b/senlin/drivers/os_test/heat_v1.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 
 class HeatClient(base.DriverBase):
diff --git a/senlin/drivers/os_test/keystone_v3.py b/senlin/drivers/os_test/keystone_v3.py
new file mode 100644
index 000000000..af37b514a
--- /dev/null
+++ b/senlin/drivers/os_test/keystone_v3.py
@@ -0,0 +1,154 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from oslo_config import cfg
+from oslo_log import log
+
+from senlin.drivers import base
+from senlin.drivers import sdk
+
+LOG = log.getLogger(__name__)
+CONF = cfg.CONF
+
+
+class KeystoneClient(base.DriverBase):
+    '''Keystone V3 driver.'''
+
+    def __init__(self, params):
+        super(KeystoneClient, self).__init__(params)
+        self.conn = sdk.create_connection(params)
+        self.session = self.conn.session
+
+    @sdk.translate_exception
+    def trust_get_by_trustor(self, trustor, trustee=None, project=None):
+        '''Get trust by trustor.
+
+        Note we cannot provide two or more filters to keystone due to
+        constraints in keystone implementation. We do additional filtering
+        after the results are returned.
+
+        :param trustor: ID of the trustor;
+        :param trustee: ID of the trustee;
+        :param project: ID of the project to which the trust is scoped.
+        :returns: The trust object or None if no matching trust is found.
+        '''
+        filters = {'trustor_user_id': trustor}
+
+        trusts = [t for t in self.conn.identity.trusts(**filters)]
+
+        for trust in trusts:
+            if (trustee and trust.trustee_user_id != trustee):
+                continue
+
+            if (project and trust.project_id != project):
+                continue
+
+            return trust
+
+        return None
+
+    @sdk.translate_exception
+    def trust_create(self, trustor, trustee, project, roles=None,
+                     impersonation=True):
+        '''Create trust between two users.
+
+        :param trustor: ID of the user who is the trustor.
+        :param trustee: ID of the user who is the trustee.
+        :param project: Scope of the trust which is a project ID.
+        :param roles: List of roles the trustee will inherit from the trustor.
+        :param impersonation: Whether the trustee is allowed to impersonate
+                              the trustor.
+        '''
+
+        if roles:
+            role_list = [{'name': role} for role in roles]
+        else:
+            role_list = []
+        params = {
+            'trustor_user_id': trustor,
+            'trustee_user_id': trustee,
+            'project_id': project,
+            'impersonation': impersonation,
+            'allow_redelegation': True,
+            'roles': role_list
+        }
+
+        result = self.conn.identity.create_trust(**params)
+
+        return result
+
+    @classmethod
+    @sdk.translate_exception
+    def get_token(cls, **creds):
+        '''Get token using given credential'''
+
+        access_info = sdk.authenticate(**creds)
+        return access_info['token']
+
+    @classmethod
+    @sdk.translate_exception
+    def get_user_id(cls, **creds):
+        '''Get ID of the user with given credential'''
+
+        access_info = sdk.authenticate(**creds)
+        return access_info['user_id']
+
+    @classmethod
+    def get_service_credentials(cls, **kwargs):
+        '''Senlin service credential to use with Keystone.
+
+        :param kwargs: An additional keyword argument list that can be used
+                       for customizing the default settings.
+        '''
+
+        creds = {
+            'auth_url': CONF.authentication.auth_url,
+            'username': CONF.authentication.service_username,
+            'password': CONF.authentication.service_password,
+            'project_name': CONF.authentication.service_project_name,
+            'user_domain_name': cfg.CONF.authentication.service_user_domain,
+            'project_domain_name':
+                cfg.CONF.authentication.service_project_domain,
+        }
+        creds.update(**kwargs)
+        return creds
+
+    @sdk.translate_exception
+    def validate_regions(self, regions):
+        """Check whether the given regions are valid.
+
+        :param regions: A list of regions for validation.
+        :returns: A list of regions that are found available on keystone.
+        """
+        region_list = self.conn.identity.regions()
+        known = [r['id'] for r in region_list]
+
+        validated = []
+        for r in regions:
+            if r in known:
+                validated.append(r)
+            else:
+                LOG.warning('Region %s is not found.', r)
+
+        return validated
+
+    @sdk.translate_exception
+    def get_senlin_endpoint(self):
+        '''Get Senlin service endpoint.'''
+        region = cfg.CONF.default_region_name
+        # TODO(Yanyan Hu): Currently, region filtering is unsupported in
+        # session.get_endpoint(). Need to propose fix to openstacksdk.
+        base = self.conn.session.get_endpoint(service_type='clustering',
+                                              interface='public',
+                                              region=region)
+
+        return base
diff --git a/senlin/drivers/openstack_test/lbaas.py b/senlin/drivers/os_test/lbaas.py
similarity index 100%
rename from senlin/drivers/openstack_test/lbaas.py
rename to senlin/drivers/os_test/lbaas.py
diff --git a/senlin/drivers/os_test/mistral_v2.py b/senlin/drivers/os_test/mistral_v2.py
new file mode 100644
index 000000000..059e61473
--- /dev/null
+++ b/senlin/drivers/os_test/mistral_v2.py
@@ -0,0 +1,42 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from senlin.drivers import base
+from senlin.drivers import sdk
+
+
+class MistralClient(base.DriverBase):
+    '''Fake Mistral V2 driver.'''
+
+    def __init__(self, params):
+        self.fake_workflow = {}
+        self.fake_execution = {}
+
+    def workflow_create(self, definition, scope):
+        return sdk.FakeResourceObject(self.fake_workflow)
+
+    def workflow_delete(self, workflow, ignore_missing=True):
+        return None
+
+    def workflow_find(self, name_or_id, ignore_missing=True):
+        return sdk.FakeResourceObject(self.fake_workflow)
+
+    def execution_create(self, name, inputs):
+        return sdk.FakeResourceObject(self.fake_execution)
+
+    def execution_delete(self, execution, ignore_missing=True):
+        return None
+
+    def wait_for_execution(self, execution, status='SUCCESS',
+                           failures=['ERROR'], interval=2,
+                           timeout=None):
+        return None
diff --git a/senlin/drivers/openstack_test/neutron_v2.py b/senlin/drivers/os_test/neutron_v2.py
similarity index 98%
rename from senlin/drivers/openstack_test/neutron_v2.py
rename to senlin/drivers/os_test/neutron_v2.py
index 2ea509712..e159c067e 100644
--- a/senlin/drivers/openstack_test/neutron_v2.py
+++ b/senlin/drivers/os_test/neutron_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 
 class NeutronClient(base.DriverBase):
diff --git a/senlin/drivers/openstack_test/nova_v2.py b/senlin/drivers/os_test/nova_v2.py
similarity index 99%
rename from senlin/drivers/openstack_test/nova_v2.py
rename to senlin/drivers/os_test/nova_v2.py
index 0d88c9926..0a44f4e50 100644
--- a/senlin/drivers/openstack_test/nova_v2.py
+++ b/senlin/drivers/os_test/nova_v2.py
@@ -15,7 +15,7 @@ import copy
 from oslo_utils import uuidutils
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 
 class NovaClient(base.DriverBase):
diff --git a/senlin/drivers/openstack_test/octavia_v2.py b/senlin/drivers/os_test/octavia_v2.py
similarity index 99%
rename from senlin/drivers/openstack_test/octavia_v2.py
rename to senlin/drivers/os_test/octavia_v2.py
index 127bd3e0a..8e18e160f 100644
--- a/senlin/drivers/openstack_test/octavia_v2.py
+++ b/senlin/drivers/os_test/octavia_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 FAKE_LB_ID = "607226db-27ef-4d41-ae89-f2a800e9c2db"
 FAKE_LISTENER_ID = "023f2e34-7806-443b-bfae-16c324569a3d"
diff --git a/senlin/drivers/openstack_test/zaqar_v2.py b/senlin/drivers/os_test/zaqar_v2.py
similarity index 95%
rename from senlin/drivers/openstack_test/zaqar_v2.py
rename to senlin/drivers/os_test/zaqar_v2.py
index 2f39dc1d5..30ca65527 100644
--- a/senlin/drivers/openstack_test/zaqar_v2.py
+++ b/senlin/drivers/os_test/zaqar_v2.py
@@ -11,7 +11,7 @@
 # under the License.
 
 from senlin.drivers import base
-from senlin.drivers.openstack_test import sdk
+from senlin.drivers import sdk
 
 FAKE_SUBSCRIPTION_ID = "0d8dbb71-1538-42ac-99fb-bb52d0ad1b6f"
 FAKE_MESSAGE_ID = "51db6f78c508f17ddc924357"
@@ -51,24 +51,24 @@ class ZaqarClient(base.DriverBase):
         return True
 
     def queue_delete(self, queue, ignore_missing=True):
-        return
+        return None
 
     def subscription_create(self, queue_name, **attrs):
         return sdk.FakeResourceObject(self.fake_subscription)
 
     def subscription_delete(self, queue_name, subscription,
                             ignore_missing=True):
-        return
+        return None
 
     def claim_create(self, queue_name, **attrs):
         return sdk.FakeResourceObject(self.fake_claim)
 
     def claim_delete(self, queue_name, claim, ignore_missing=True):
-        return
+        return None
 
     def message_delete(self, queue_name, message, claim_id=None,
                        ignore_missing=True):
-        return
+        return None
 
     def message_post(self, queue_name, message):
         return sdk.FakeResourceObject(self.fake_message)
diff --git a/senlin/drivers/openstack/sdk.py b/senlin/drivers/sdk.py
similarity index 89%
rename from senlin/drivers/openstack/sdk.py
rename to senlin/drivers/sdk.py
index d9257d7bf..7641b9579 100644
--- a/senlin/drivers/openstack/sdk.py
+++ b/senlin/drivers/sdk.py
@@ -16,16 +16,15 @@ SDK Client
 import sys
 
 import functools
-from oslo_config import cfg
-from oslo_log import log as logging
-import six
-
 from openstack import connection
 from openstack import exceptions as sdk_exc
 from openstack import profile
 from openstack import utils as sdk_utils
+from oslo_config import cfg
+from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from requests import exceptions as req_exc
+import six
 
 from senlin.common import exception as senlin_exc
 
@@ -138,3 +137,20 @@ def authenticate(**kwargs):
     }
 
     return access_info
+
+
+class FakeResourceObject(object):
+    '''Generate a fake SDK resource object based on given dictionary'''
+    def __init__(self, params):
+        for key in params:
+            setattr(self, key, params[key])
+
+    def to_dict(self):
+        '''Override this function in subclass to handle special attributes'''
+        data = {}
+        for attr in dir(self):
+            if not attr.startswith('__'):
+                # Exclude built-in attributes of python object
+                data[attr] = getattr(self, attr)
+
+        return data
diff --git a/senlin/engine/actions/cluster_action.py b/senlin/engine/actions/cluster_action.py
index 846fe4213..b7dcb49fc 100755
--- a/senlin/engine/actions/cluster_action.py
+++ b/senlin/engine/actions/cluster_action.py
@@ -301,6 +301,13 @@ class ClusterAction(base.Action):
         result, reason = self._update_nodes(profile_id, self.entity.nodes)
         return result, reason
 
+    def _handle_lifecycle_timeout(self, child):
+        for action_id, node_id in child:
+            status = ao.Action.check_status(self.context, action_id, 0)
+            if (status == consts.ACTION_WAITING_LIFECYCLE_COMPLETION):
+                ao.Action.update(self.context, action_id,
+                                 {'status': base.Action.READY})
+
     def _delete_nodes(self, node_ids):
         action_name = consts.NODE_DELETE
 
@@ -319,11 +326,10 @@ class ClusterAction(base.Action):
             lifecycle_hook_params = lifecycle_hook.get('params')
             if lifecycle_hook_type == "zaqar":
                 lifecycle_hook_target = lifecycle_hook_params.get('queue')
-            elif lifecycle_hook_type == "webhook":
-                lifecycle_hook_target = lifecycle_hook_params.get('url')
             else:
-                return self.RES_ERROR, _("Invalid lifecycle hook type "
-                                         "specified in deletion policy")
+                # lifecycle_hook_target = lifecycle_hook_params.get('url')
+                return self.RES_ERROR, _("Lifecycle hook type '%s' is not "
+                                         "implemented") % lifecycle_hook_type
 
         child = []
         for node_id in node_ids:
@@ -355,22 +361,18 @@ class ClusterAction(base.Action):
                 ao.Action.update(self.context, action_id,
                                  {'status': status})
                 if lifecycle_hook:
-                    if lifecycle_hook_type == "zaqar":
-                        # post message to zaqar
-                        kwargs = {
-                            'user': self.context.user_id,
-                            'project': self.context.project_id,
-                            'domain': self.context.domain_id
-                        }
+                    # lifecycle_hook_type has to be "zaqar"
+                    # post message to zaqar
+                    kwargs = {
+                        'user': self.context.user_id,
+                        'project': self.context.project_id,
+                        'domain': self.context.domain_id
+                    }
 
-                        notifier = msg.Message(lifecycle_hook_target, **kwargs)
-                        notifier.post_lifecycle_hook_message(
-                            action_id, node_id,
-                            consts.LIFECYCLE_NODE_TERMINATION)
-                    else:
-                        reason = _("Lifecycle hook type '{}' is not "
-                                   "implemented").format(lifecycle_hook_type)
-                        return self.RES_ERROR, reason
+                    notifier = msg.Message(lifecycle_hook_target, **kwargs)
+                    notifier.post_lifecycle_hook_message(
+                        action_id, node_id,
+                        consts.LIFECYCLE_NODE_TERMINATION)
 
             res = None
             if lifecycle_hook:
@@ -378,13 +380,7 @@ class ClusterAction(base.Action):
                 res, reason = self._wait_for_dependents(lifecycle_hook_timeout)
 
                 if res == self.RES_LIFECYCLE_HOOK_TIMEOUT:
-                    for action_id, node_id in child:
-                        status = ao.Action.check_status(self.context,
-                                                        action_id, 0)
-                        if (status ==
-                                consts.ACTION_WAITING_LIFECYCLE_COMPLETION):
-                            ao.Action.update(self.context, action_id,
-                                             {'status': base.Action.READY})
+                    self._handle_lifecycle_timeout(child)
 
             if res is None or res == self.RES_LIFECYCLE_HOOK_TIMEOUT:
                 dispatcher.start_action()
diff --git a/senlin/tests/unit/drivers/test_ceilometer_v2.py b/senlin/tests/unit/drivers/test_ceilometer_v2.py
deleted file mode 100644
index a2e837f82..000000000
--- a/senlin/tests/unit/drivers/test_ceilometer_v2.py
+++ /dev/null
@@ -1,108 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-import mock
-
-from senlin.drivers.openstack import ceilometer_v2
-from senlin.drivers.openstack import sdk
-from senlin.tests.unit.common import base
-from senlin.tests.unit.common import utils
-
-
-class TestCeilometerV2(base.SenlinTestCase):
-
-    def setUp(self):
-        super(TestCeilometerV2, self).setUp()
-
-        self.ctx = utils.dummy_context()
-        self.conn_params = self.ctx.to_dict()
-        self.mock_conn = mock.Mock()
-        self.mock_create = self.patchobject(
-            sdk, 'create_connection',
-            return_value=self.mock_conn)
-
-    def test_init(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        self.mock_create.assert_called_once_with(self.conn_params)
-        self.assertEqual(self.mock_conn, d.conn)
-
-    def test_alarm_create(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        d.alarm_create(name='test_alarm')
-        self.mock_conn.telemetry.create_alarm.assert_called_once_with(
-            name='test_alarm')
-
-    def test_alarm_delete(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        d.alarm_delete('foo', True)
-        self.mock_conn.telemetry.delete_alarm.assert_called_once_with(
-            'foo', True)
-
-        self.mock_conn.telemetry.delete_alarm.reset_mock()
-
-        d.alarm_delete('foo', False)
-        self.mock_conn.telemetry.delete_alarm.assert_called_once_with(
-            'foo', False)
-
-        self.mock_conn.telemetry.delete_alarm.reset_mock()
-
-        d.alarm_delete('foo')
-        self.mock_conn.telemetry.delete_alarm.assert_called_once_with(
-            'foo', True)
-
-    def test_alarm_find(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        d.alarm_find('fakeid', True)
-        self.mock_conn.telemetry.find_alarm.assert_called_once_with(
-            'fakeid', True)
-
-        self.mock_conn.telemetry.find_alarm.reset_mock()
-
-        d.alarm_find('fakeid', False)
-        self.mock_conn.telemetry.find_alarm.assert_called_once_with(
-            'fakeid', False)
-
-        self.mock_conn.telemetry.find_alarm.reset_mock()
-
-        d.alarm_find('fakeid')
-        self.mock_conn.telemetry.find_alarm.assert_called_once_with(
-            'fakeid', True)
-
-    def test_alarm_get(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        d.alarm_get('fakeid')
-        self.mock_conn.telemetry.get_alarm.assert_called_once_with('fakeid')
-
-    def test_alarm_list(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        d.alarm_list()
-        self.mock_conn.telemetry.alarms.assert_called_once_with()
-
-        self.mock_conn.telemetry.alarms.reset_mock()
-
-        d.alarm_list(name='fakename')
-        self.mock_conn.telemetry.alarms.assert_called_once_with(
-            name='fakename')
-
-    def test_alarm_update(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        attrs = {'enabled': False}
-        d.alarm_update('fakeid', **attrs)
-        self.mock_conn.telemetry.update_alarm.assert_called_once_with(
-            'fakeid', **attrs)
-
-    def test_sample_create(self):
-        d = ceilometer_v2.CeilometerClient(self.conn_params)
-        attrs = {'foo': 'bar'}
-        d.sample_create(**attrs)
-        self.mock_conn.telemetry.create_sample.assert_called_once_with(
-            foo='bar')
diff --git a/senlin/tests/unit/drivers/test_cinder_v2.py b/senlin/tests/unit/drivers/test_cinder_v2.py
index 161b6cefa..317c9dda5 100644
--- a/senlin/tests/unit/drivers/test_cinder_v2.py
+++ b/senlin/tests/unit/drivers/test_cinder_v2.py
@@ -12,8 +12,8 @@
 
 import mock
 
-from senlin.drivers.openstack import cinder_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import cinder_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_glance_v2.py b/senlin/tests/unit/drivers/test_glance_v2.py
index 982fd675e..1bd4f5d7f 100644
--- a/senlin/tests/unit/drivers/test_glance_v2.py
+++ b/senlin/tests/unit/drivers/test_glance_v2.py
@@ -12,8 +12,8 @@
 
 import mock
 
-from senlin.drivers.openstack import glance_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import glance_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_heat_v1.py b/senlin/tests/unit/drivers/test_heat_v1.py
index c0bbb0058..63044f50b 100644
--- a/senlin/tests/unit/drivers/test_heat_v1.py
+++ b/senlin/tests/unit/drivers/test_heat_v1.py
@@ -13,8 +13,8 @@
 import mock
 from oslo_config import cfg
 
-from senlin.drivers.openstack import heat_v1
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import heat_v1
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_keystone_v3.py b/senlin/tests/unit/drivers/test_keystone_v3.py
index 447032a30..475af7ad1 100644
--- a/senlin/tests/unit/drivers/test_keystone_v3.py
+++ b/senlin/tests/unit/drivers/test_keystone_v3.py
@@ -15,8 +15,8 @@ import copy
 import mock
 from oslo_config import cfg
 
-from senlin.drivers.openstack import keystone_v3 as kv3
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import keystone_v3 as kv3
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_lbaas_driver.py b/senlin/tests/unit/drivers/test_lbaas.py
similarity index 99%
rename from senlin/tests/unit/drivers/test_lbaas_driver.py
rename to senlin/tests/unit/drivers/test_lbaas.py
index df275bcb2..be93c020a 100644
--- a/senlin/tests/unit/drivers/test_lbaas_driver.py
+++ b/senlin/tests/unit/drivers/test_lbaas.py
@@ -17,9 +17,9 @@ from oslo_context import context as oslo_context
 
 from senlin.common import exception
 from senlin.common.i18n import _
-from senlin.drivers.openstack import lbaas
-from senlin.drivers.openstack import neutron_v2
-from senlin.drivers.openstack import octavia_v2
+from senlin.drivers.os import lbaas
+from senlin.drivers.os import neutron_v2
+from senlin.drivers.os import octavia_v2
 from senlin.engine import node as nodem
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
diff --git a/senlin/tests/unit/drivers/test_mistral_v2.py b/senlin/tests/unit/drivers/test_mistral_v2.py
index 00f287f3b..5e3ef7b57 100644
--- a/senlin/tests/unit/drivers/test_mistral_v2.py
+++ b/senlin/tests/unit/drivers/test_mistral_v2.py
@@ -12,8 +12,8 @@
 
 import mock
 
-from senlin.drivers.openstack import mistral_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import mistral_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_neutron_v2_driver.py b/senlin/tests/unit/drivers/test_neutron_v2.py
similarity index 98%
rename from senlin/tests/unit/drivers/test_neutron_v2_driver.py
rename to senlin/tests/unit/drivers/test_neutron_v2.py
index 85adcc887..5d5062096 100644
--- a/senlin/tests/unit/drivers/test_neutron_v2_driver.py
+++ b/senlin/tests/unit/drivers/test_neutron_v2.py
@@ -13,8 +13,8 @@
 import mock
 from oslo_utils import uuidutils
 
-from senlin.drivers.openstack import neutron_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import neutron_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_nova_v2.py b/senlin/tests/unit/drivers/test_nova_v2.py
index 86f1db8e4..f86107567 100644
--- a/senlin/tests/unit/drivers/test_nova_v2.py
+++ b/senlin/tests/unit/drivers/test_nova_v2.py
@@ -13,8 +13,8 @@
 import mock
 from oslo_config import cfg
 
-from senlin.drivers.openstack import nova_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import nova_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_octavia_v2.py b/senlin/tests/unit/drivers/test_octavia_v2.py
index 182695643..b5e7fb81f 100644
--- a/senlin/tests/unit/drivers/test_octavia_v2.py
+++ b/senlin/tests/unit/drivers/test_octavia_v2.py
@@ -12,8 +12,8 @@
 
 import mock
 
-from senlin.drivers.openstack import octavia_v2
-from senlin.drivers.openstack import sdk
+from senlin.drivers.os import octavia_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/drivers/test_sdk.py b/senlin/tests/unit/drivers/test_sdk.py
index c8058b159..7d7f9f9da 100644
--- a/senlin/tests/unit/drivers/test_sdk.py
+++ b/senlin/tests/unit/drivers/test_sdk.py
@@ -20,7 +20,7 @@ from requests import exceptions as req_exc
 import six
 
 from senlin.common import exception as senlin_exc
-from senlin.drivers.openstack import sdk
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 
 
diff --git a/senlin/tests/unit/drivers/test_zaqar_v2.py b/senlin/tests/unit/drivers/test_zaqar_v2.py
old mode 100755
new mode 100644
index be0d0e884..f04e4734e
--- a/senlin/tests/unit/drivers/test_zaqar_v2.py
+++ b/senlin/tests/unit/drivers/test_zaqar_v2.py
@@ -14,8 +14,8 @@ import mock
 
 from openstack import exceptions as sdk_exc
 
-from senlin.drivers.openstack import sdk
-from senlin.drivers.openstack import zaqar_v2
+from senlin.drivers.os import zaqar_v2
+from senlin.drivers import sdk
 from senlin.tests.unit.common import base
 from senlin.tests.unit.common import utils
 
diff --git a/senlin/tests/unit/engine/actions/test_delete.py b/senlin/tests/unit/engine/actions/test_delete.py
index 789ff429e..8a8fef5d1 100755
--- a/senlin/tests/unit/engine/actions/test_delete.py
+++ b/senlin/tests/unit/engine/actions/test_delete.py
@@ -286,8 +286,7 @@ class ClusterDeleteTest(base.SenlinTestCase):
         # assertions (other assertions are skipped)
         self.assertEqual(action.RES_ERROR, res_code)
         self.assertEqual(
-            'Invalid lifecycle hook type specified in deletion policy',
-            res_msg)
+            "Lifecycle hook type 'unknown_type' is not implemented", res_msg)
 
     @mock.patch.object(ao.Action, 'update')
     @mock.patch.object(ab.Action, 'create')
@@ -317,8 +316,7 @@ class ClusterDeleteTest(base.SenlinTestCase):
         # assertions (other assertions are skipped)
         self.assertEqual(action.RES_ERROR, res_code)
         self.assertEqual(
-            'Lifecycle hook type \'webhook\' is not implemented',
-            res_msg)
+            "Lifecycle hook type \'webhook\' is not implemented", res_msg)
 
     @mock.patch.object(ao.Action, 'update')
     @mock.patch.object(ab.Action, 'create')
diff --git a/setup.cfg b/setup.cfg
index c9bd53a67..c588afc99 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -41,8 +41,8 @@ oslo.policy.policies =
     senlin = senlin.common.policies:list_rules
 
 senlin.drivers =
-    openstack = senlin.drivers.openstack
-    openstack_test = senlin.drivers.openstack_test
+    openstack = senlin.drivers.os
+    openstack_test = senlin.drivers.os_test
 
 senlin.profiles =
     os.heat.stack-1.0 = senlin.profiles.os.heat.stack:StackProfile